Lubricant and method of manufacturing same



Patented Apr. 15, 1941 UNITED-"STATES PATENT OFFICE LUBRICANT AND METHOD OF MANI J FACTURING SAME Anthony H. Gleason, Elizabeth, N. 1., a ssignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application December as, 1937,

- Serial No. isms:

14 Claims.

The present. invention relates to improved lubricating oils, specifically to oils of low pour point and further to substances having wax modifying properties which may be used to reduce the pour point of oils and to assist in the .removal 01 waxy constituents from oils conof lubricating oils so as to prevent solidification or congelation of the oil at its normal pour point. In this way an oil which normally becomes solid at say 30, or 40 or 50 or even 75 F. may be caused to remain liquid even as low as or 10 or 0 or below, without removal of any of the wax therefrom. The present invention relates to a new class of substances which possesses both or the two enumerated properties to a more or less substantial degree.

The materials which form the basis of th 'present invention are condensation products of various compounds. The condensation is carried out with the assistance of aluminum chloride, zinc chloride, boron fluoride or other known condensation agents of this class and ordinarily at room temperatures such as 70 to 100 F, and generally not above say, 250 to 300 F., although the allowable limits may vary somewhat when different materials are used. If desired, solvents may be used during the condensation and for that purpose highly saturated kerosene or heavy naphtha, or other solvent may be used. If

polymerization goes too far, insoluble materials' of a rubbery character result which are, of course, undesirable. This may be prevented by limiting the time 01' reaction and by addition of saturated acids, esters, alcohols and the like to the reaction mixture.

The polymerization and condensation can also be conducted at higher temperatures in the presence of less active catalysts such as the should be substantially so and should contain at least one reactive group in addition to the hydroxyl group. This reactive group may be.

olefinic as in the unsaturatedalcohols such as oleyl or other unsaturated alcohols but the reactive. group may also be a halogen for example chlorine as in the chlor-stearyl alcohol. The chlorinated or oleilnic compounds may be used as such and the condensation is carried out in the same way as indicated abovewith the aluminum chloride type of catalysts at substantially the same temperatures mentioned. During this process a considerable amount of hydrochloric acid may be evolved. Ii preferred, the halogenated compound may be removed from the material prior to condensation in any known manner such as by application of heat, preterably in the presence of such material as barium chloride so as to split oif hydrochloric acid leaving unsaturated material for condensation; Unsaturated or an already partially unsaturated material may be increased by this or by other suitable means before condensation.

As to the particular materials which may be used, acids of the type of stearic or palmitic are suitable, but since these are saturated they should be treated as above indicated either to render them unsaturated or to make their halogen derivatives. Generally speaking, straight chain saturated acids produced by the oxidation of paraflln wax by blowing with air, preferably in presence of catalysts of the siccative type which range from C 10 to C 22 or more, may all be used, or mixtures maybe used just as the natural fatty acids would be used. Naturally unsaturated acids may also be used such as oleic, erucic, elaidic or crotonic, and highly unsaturated acids can also be used such as linoleic, or their hydroxy derivatives such as naphtholic. Likewise, the acetylenic acids such as behenolic or stearolic are suitable.

The esters of all of these acids such as methyl, ethyl or propyl esters may be used, or even higher alkyl esters such as the drying or semi-drying oils, but the reaction of such materials is so sluggish that they are not nearly-so desirable as the lower alkyl esters for the present purposes. In fact, the lower alkyl esters are probably more desirable than the acids themselves. Alcohols,

ketones or ethers are useful for the present purpose exactly as the esters, and the substances of this class should contain straight hydrocarbon chains of, at least, 10 or 12 carbon atoms, as indicated above. If they are already unsaturated they may be used as such, as indicated before, but if saturated they may be first halogenated or rendered unsaturated by the methods indicated above, or by similar suitable means.

The materials which have been listed above falling in the classes of acids, esters, alcohols, ethers, ketones and the like may be used alone, but it is preferable to carry out the condensation in the presence of a cyclic compound such as benzol or naphthalene or their hydrogenated or.alkylated derivatives such as tolucl or xylol or ethylnaphthalene, tetralin, hexalin. decalin, and the like. The presence of a hydroxy group in the cyclic substance is permissible although not specially desirable, as illustrated by the phenols and naphthols or cyclic alcohols such as cyclohexanol and the like. Nitrated aromatics can be used as well as amines such as aniline and naphthylamine. In addition to the cyclic compounds listed above. cyclic terpenes may also be used.

The condensation which is described above is more than a simple union of two molecules'since very heavypolymers are sought to be produced and these materials are particularly desirable. The polymers which are to be used are those having molecular weights well above 600 and since the method produces materials of a series of molecular weights, it is difficult to say which are those responsible for this specific action. It has been found that materials of molecular weights of 1000 or 2000 and even higher are present. The crude reaction product may be purified by the ordinary methods known in the art; for example, by washing with water or alkali to remove traces of the aluminum chloride, or treated with sulphuric acid of a strength insufficient to carbonize or suiphonate, and the lighter fractions which do not possess pour depressing properties may be removed by distillation, preferably under vacuum up to a boiling point of say 475 to 575 F.

(1 millimeter vacuum) so as to concentrate the valuable heavy polymers. Distillation with steam can also be used and care should be taken not to crack the product.

The exact structure of these materials after condensation is, of course, unknown but some of the oxygen is still present in the final product in addition to carbon and hydrogen and this can be demonstrated by analysis. If acids or esters are used the oxygen remains in an acidic form, that is to say, the carboxyl group is not destroyed since acid or saponification values can be obtained. This acid group may also be esterified, neutralized or otherwise modified.

The heavy polymers produced by the methods indicated above may be added to lubricating oils in order to increase their film strength on the one hand, and to reduce pour point coused by the presence of waxy constituents. The polymers can be used in wax free oils if desired, but it is generally preferred to use the material in a waxy oil with a pour point of 30 or higher. A part of the wax, of course, may be removed if desired, and in the case of naturally low pour oils we have found it desirable even to add substantial quantities of wax along with the addition agent so as to improve the oil in regard to its viscosity-temperature curve and at the same time maintain a low pour point. For the present purpose the amount of polymer to be added is always below' 10% and generally below even 5 depending on whether a more or less concentrated material may have been produced. If a heavy polymer having an average molecular weight of say 600 to 700 is produced by distilling 011 light fractions, then 1 to 4% is generally sufiicient to Stearone (di-heptadecyl-ketone) Cn u CnHu

was prepared by the thermal decomposition (under high vacuum) of dry calcium stearate. The following reaction takes place:

The stearone which forms as a result of the thermal decomposition distilled out from the re- CO+CaC 0;

action mixture and was collected in a separate receiver. The crude stearone was 'purified by first drying (distillation in xylene) and then removing all light boiling materials by distillation under high vacuum (5 mm. Hg pressure) to 250 C. The chief impurity removed by such a pro cedure was stearic acid. The residue of this distillation was the purified stearone used in the subsequent steps.

The stearone so prepared was found to be a light yellow waxy substance of high melting point (157 F.)

Seventy-five grams of stearone. prepared as described above, was chlorinated by passing chlorine gas into the molten stearone maintained at 210-230 F. Reaction with the chlorine gas was very rapid, 16.1 grams of chlorine being absorbed in minutes. This corresponds to a chlorine content of 9.7

The following proportion of reagents were used:

, Grams Chlorinated stearone 75 Naphthalene 9.75- AlCla 2.0

Seventy-five grams of this chlorinated stearone and 9.75 grams of naphthalene were dissolved in 150 cc. of tetrachlorethane and 2.0 grams AlCh were added in two one-gram portions to the reaction mixture, while shaking at room temperature. The reaction mixture was then warmed to F. for two hours and then diluted with 500 cc. of kerosene and neutralized by pouring into alcohol and water. After settling in a. funnel, the kerosene extract was washed with water and then distilled with fire and steam to 600 F. to remove solvent and unreacted material. 31.8 grams of a viscous residue was then obtained, corresponding to a 43% yield based on the stearone.

The pour depressor potency of the stearonenaphthalene condensation product was tested by blending in a waxy petroleum lubricating oil. The following results were obtained:

Pour point,

Original oil +30 Original oil+ 1 stearone-naphthalene product 5 Original oil+'3% stearone-naphthalene product 5 It is interesting to note that 1% condensation of the material is as eilective as 3% Example II A mixture of 75 grams of the chlorinated stearone described above and grams of finely divided Attapulgus clay was heated slowly with stirring to 525 F. and was maintained at this temperature for two hours. Hydrogen chloride was evolved vigorously at first and the reaction mixture became very thick and viscous, the evolution of hydrogen chloride having practically ceased at the end of this time. The reaction mixture was then cooled to 120 E, was diluted with 500 cc. of kerosene and was filtered. The kerosene filtrate was distilled under a vacuum of 5 mm. mercury pressure absolute to 500 F. to remove the solvent and any unreacted materials. There was thus obtained as distillation residue 35 grams of a viscous polymer oil of high molecular weight.

1% of this polymer product was added to a waxy lubricating oil having a pour point of 30 F. The pour point of the resulting blend was '--30 F.

Ethers may be ,used in place of the ketones in -the above examples and polymer products having pour depressant properties may be similarly prepared therefrom.

In the following claims the term "polymer is used to describe an eflective combination of the initial materials or heavy molecular weight in substantial quantities, that is to say, with molecular weights above about 600 and ranging through 1000 to 2000. These heaviest materials cannot be vaporized or only with very great dimculty, without decomposition. It is to be understood that ii the initial materials are saturated they must be rendered unsaturated or else must be halogenated, or if they are unsaturated originally they may be polymerized as such.

My invention is not to be limited by any theory of the operation of the condensation, nor to the use of any particular starting materials, but only to the claims in which I wish to claim all novelty inherent in the process.

I claim:

1. An improved lubricating 011 comprising a viscous waxy hydrocarbon oil containing a small proportion of a polymerized oxygen-containing aliphatic compound having an oxygen atom connected only to carbon and having a chain of more than ten carbon atoms, the polymer product containing a substantial proportion of fractions with a molecular weight above about 600 and soluble in the oil.

2. Composition according to claim 1, in which the said aliphatic compound is unsaturated.

3. Composition according to claim 1, in which the addition agent is a polymer of an ether.

4. Composition according to claim 1, in which the addition agent is a polymer of a ketone.

.5. An improved lubricating oil comprising a viscous waxy hydrocarbon oil containing a small proportion of a polymer-condensation product of an oxygen-containing aliphatic compound, having an oxygen atom connected only to carbon and having a chain of more than ten carbon atoms, with a cyclic carbon compound, the polymer product containing a substantial proportion of fractions with a molecular weight above about 600 and soluble in the oil. 1

6. Composition according to claim 5, in which the polymer is a condensation product of an unsaturated aliphatic compound and an aromatic compound. [I

7. An improved lubricating oil comprising a viscous petroleum hydrocarbon fraction containing a solid waxy constituent in proportion suflicient to give a relatively high pour-point blended with a suflicient amount of a, high molecular weight ether condensation product containing a long aliphatic hydrocarbon chain to reduce the pour point of said hydrocarbon fraction,

8. An improved lubricating oil comprising a viscous petroleum hydrocarbon fraction containing a solid waxy constituent in proportion sumcient to give a relatively high pour-point blended with about 1% of a high molecular weight ether condensation product containing a long aliphatic hydrocarbon chain.

9. An improved lubricating oil comprising a viscous waxy hydrocarbon oil containing a small proportion of a polymerized oxygen-containing aliphatic compound having an oxygen atom connected only to carbon and having a chain of more than 10 carbon atoms and also having not more than one oxygen atom attached to any one carbon atom, the polymer product containing a substantial proportion of fractions with a molecular weight above about 600 and soluble in the oil.

10. Composition according to claim 9, in which the said polymer-was produced by condensation at 70 to 300 F. with an aromatic compound in the presence of a condensation catalyst.

1 1. An improved lubricating 011 comprising a viscous waxy hydrocarbon oil containing a small proportion of a polymerized compound selected from the group consisting of chlorinated and unsaturated oxygen-containing compounds selected from the group consisting of ethers and ketones containing at least one aliphatic chain of more than 10 carbon atoms, the polymer product containing a substantial proportion of fractions with a molecular weight above about 600 and soluble in the oil.

12. An improved lubricating oil comprising a viscous waxy hydrocarbon oil containing a small proportion of a polymer-condensation product of a compound selected from the group consisting of chlorinated and unsaturated oxygen-containing compounds selected from the group consisting of ethers and ketones containing at least one aliphatic chain of more than 10 carbon atoms, with an aromatic compound, the polymer product containing a substantial proportion of fractions with a molecular weight above about 600 and soluble in the oil.

13. A lubricating oil comprising a waxy hydrocarbon oil and a small proportion. of polymerized chlorinated stearone having a molecular weight above about 600 and soluble in the oil.

14. A lubricating oil comprising a waxy hydrocarbon oil containing a small proportion of a polymer-condensation product of chlorinated stearone with naphthalene, the polymer product, containing a substantial proportion of fraction with a molecular weight above about 600 and soluble in the oil.

ANTHONY H. GLEASON. 

